aptitude -t experimental install kde4 fails because kdebase-workspace cannot be installed. Aptitude is looking for version 4:4.1.0-2, but for i386, the highest version in experimental is still only 4:4.1.0-1. My options appear to be: 1. Build it myself, from the source package 2. Wait for 4:4.1.0-2 to be uploaded. Tim Fairbank